ahead how another attack led to change in california >> jeff: in the san francisco bay area this weekend police collected more than 500 handguns as part of a holiday gun buyback. that's one approach meant to reduce gun violence in california. lee cowan tonight reports on another effort that came in response to a 1989 school shooting. >> when it happened at cleveland elementary in stockton california some 23 years ago many thought a school shooting couldn't get any worse. a troubled man with an assault rifle killed five students and wounded 29 others. while it sadly wasn't the last or even worse school shooting in the country, it did lead to california's ban on assault weapons. the first in the nation. it wasn't a perfect solution. in the eyes of gun enthusiasts but at least the ban was an effort to do something to stem the violence. in the wake of connecticut, many california leaders wonder where that resolve is today. >> if not after this, then seriously just shame on all of us, seriously, shame on the leadership of this country. >> reporter: gavin newsom is california's lt. governor bu